Unsaponifiable Matter of Coffee

The unsaponifiable matter of coffee, which represents approximately 15-18% of coffee oil, is an extremely complex fraction that contains sterols, tocopherols, and high amounts of diterpene alcohols. This fraction has attracted increasing interest in recent years, not only because of its possible physiological effects, but also because of its extreme importance and usefulness as fingerprint for the identification of the botanical and geographical origin of coffee beans and for the authentication of coffee. For instance, 16-O-methylcafestol, which covers one-quarter of the unsaponifiable matter of green and roasted Robusta oil, is absent in Arabica, whereas diterpene E has been detected exclusively in roasted Arabica. Additionally, Robusta contains fivefold higher amounts of Δ5-avenasterol than Arabica, which shows higher content of tochopherols, especially beta-tocopherol. The purpose of this chapter is to discuss the influence of the species and manufacturing process conditions on the qualitative and quantitative composition of the unsaponifiable matter of coffee. © 2015 Elsevier Inc. All rights reserved.